Rotary cutting tools 14 are used in meat processing plants. An electric motor 12 is used to power the rotary cutting tool 14. The motor 12 connects to a flexible drive shaft assembly 20 or flexshaft assembly which is coupled to a gear of the rotary cutting tool 14.
One problem with the design of existing flexshaft assemblies 20 is that rotation of the flexshaft assembly within a sealed flexible tubular casing 22 causes lubricant to be forced out of the tubular casing. The flexshaft assembly 20 is comprised of wires wrapped around a core wire. The tubular casing 22 helps protect the flexshaft assembly from the environment and protects workers from the rotating shaft. The wires are wrapped in a direction that causes a screwing effect downward from the motor 12 to the rotary cutting tool 14. This causes the lubricant to be pumped out of the casing 22 as indicated by arrow 23 and reduces the life of the flexshaft assembly 20.
Unsuccessful attempts have been made to prevent the helical wires from pumping the lubricant out of the casing 22. For example, sealing around the flexshaft assembly has been unsuccessful, because there are gaps between the wires that allow the lubricant to escape. One solution was to crimp a metal bearing onto the flexshaft assembly and run the metal bearing inside of a TEFLON bearing. However, this seal is not always 100% effective.